• Journal of the Korean Wood Science and Technology
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• 제42권4호
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• pp.483-490
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• 2014

마이크로피브릴 셀룰로오스(MFC) 강화 polybutylene succinate (PBS) 나노복합재료의 성질에 미치는 MFC 첨가량 및 커플링제로서 polymeric methylene diphenyl diisocyanate (pMDI)의 첨가 영향을 조사하였다. 나노복합재료의 인장강도 및 탄성율은 MFC의 첨가량이 증가함에 따라 향상되었다. 또한 pMDI 첨가에 의하여 인장강도 및 탄성율은 증가하였으며, MFC첨가량이 증가하면서 그 경향이 더욱 뚜렷하였다. PBS/MFC (70/30) 복합재료에서는 인장강도가 pMDI(1 중량부)의 첨가에 의하여 약 1.5배 이상 향상되었다. 이러한 향상은 pMDI 첨가에 의한 MFC의 분산성 및 메트릭스 고분자와의 계면접착성 향상에 기인하며, 전자현미경을 이용한 파단면 관찰로 확인하였다. 또한, pMDI 첨가에 의하여 나노복합재료의 열적 안정성도 향상되었다.

• KSBB Journal
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• 제29권3호
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• pp.155-164
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• 2014

Succinic acid, a representative biomass-derived platform chemical, is a major fermentation product of Actinobacillus succinogenes. It is well known that carbon dioxide is consumed during the succinate fermentation, but the biochemical mechanism behind this phenomenon is not yet understood well. In this study, it was found that the addition of carbonic anhydrase (CA)s into media significantly enhances the succinic acid production by A. succinogenes during the fermentation supplied with carbon dioxide. It is likely that the (bi) carbonate produced by the CA activity from gaseous carbon dioxide is favoured by A. succinogenes for consumption and utilization. Therefore, the $MgCO_3$ requirement could be significantly reduced without compromising the succinate productivity. Furthermore, because of too high price of the commercial carbonic anhydrase, it was undertaken to economically overproduce a cyanobacterial carbonic anhydrase by the use of a recombinant Pichia pastoris. An expression vector system was constructed with the carbonic anhydrase gene PCR-cloned from Cyanobacterium Synechocystis sp., and introduced into P. pastoris for fermentation studies. About 95.9 g/L of succinic acid was produced in the production medium with 30 ppm of carbonic anhydrase, approximately 2 fold higher productivity compared to the parallel process with no supplementation of the enzyme. It is expected that this method can provide a valuable way of overcoming inefficiencies inherent in gas supply during $CO_2$-based bioprocesses like succinic acid fermentation.

• Journal of Plant Biology
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• 제12권2호
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• pp.7-14
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• 1969

Dunaliella tertiolecta did not show any increase in respiration rate when supplied with glucose, glycerol, sucrose, L-alanine, acetate, pyruvate and succinate. This was in contrast to Chlorella pyrenoidosa, which, under identical conditions, showed significant increase when supplied with glucose or acetate but not with the other compounds. Production of 14CO2 from added 14C-glucose in D. tertiolecta was lower than the other 14C-labelled substrates: L-alinine, glycerol, succinate, but higher than 14C-sucrose addition. And it was also lower than C. pyrenoidosa experiments which was added 14C-glucose as a substrate. Light reduced amounts of labelled carbon dioxide from 14C-glucose or 14C-acetate and increased incorporation of 14C from the substrates to cell materials in either D. tertiolecta or C. pyrenoidosa. The contribution of 14C from 14C-glucose to 14CO2 in cell-free system of D. tertiolecta were much higher than in whole cell suspension. It was contrast to C. pyrenoidosa which were showed reduction of 14CO2 production in cell-free systems than whole cell suspensions. When cell-free systems of D. tertiolecta and C. pyrenoidosa were supplied with ATP, NAD, NADP or/and hexokinase, it was remarkably increased production of 14CO2 from the substrates than the control. It was concluded that the low ability of D. tertiolecta to metabolize glucose were caused by the impermeability of the cell membrane to glucose and were not due to deficiencies of enzyme systems concerning glucose metabolism. In the cell-free systems, it seemed to be more active pentose phosphate pathway than glycolytic pathway in D. tertiolecta.

• 수산해양기술연구
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• 제47권1호
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• pp.10-17
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• 2011

Biodegradable octopus pot was developed to reduce plastic pollution problem in the sea and fishing trouble between fishermen. It can be expect to recycle other wasted biodegrade fishing gear. Experimental fishing was carried out to understand the difference in fishing efficiency between Polyethylene (PE) octopus pots and biodegradable (Polybutylene Succinate and Polybutylene adipate-co-terephthalate) octopus pots which was tried to make in this study in the sea. There were caught by 237 numbers of fishing during the experimental period. Among the 237 numbers of fishing, 160 or 67.5% were PE pots which were more than the biodegradable pots. A comparison of the monthly catches between the PE pots and biodegradable pots shows that the catches were overall higher in the PE pots than in the other pots. The result is very similar with the comparison of total catches by each type of the pots. In terms of bycatch, the number of species, amount of catches and the number of fishing with bycatch were more significant in the biodegradable pots than in the PE pots.

• KSBB Journal
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• 제17권2호
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• pp.182-188
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• 2002

푸마르산으로부터 숙신산 생물전환을 위하여 E. faecalis RKY1을 HFBR에 친정화하여 연속생산 공정에 대한 가능성을 모색하였다. E. faecalis RKY1은 실관의 spongy 부분에 효과적으로 고정화되었으며, transverse mode로 HFBR 조업시 실관가닥이 50개 및 200개일 경우 거의 비슷한 경향을 나타냈다. 또한 배지의 공급속도를 0.25, 0.5, 1.0 mL/min로 증가시키면서 조업한 결과, 정상상태에 도달하는 시간이 각각 24, 12, 9시간으로서 유속이 증가할수록 정상상태에 도달하는 시간은 단축되었지만, 반응기 내의 기질 및 생성물 분포는 그 변화가 심하였다. 실관 생물반응기를 이용하여 숙신산 생물 전환시 배지의 공금 유속이 증가할수록 숙신산 생산성은 증가하였지만 전환수율이 감소하여 미반응 푸마르산은 증가하였다. 최대 숙신산 생산성 및 이 때의 수율은 푸마르산염 농도 80 g/L 및 배지 공금 유속 2.0 mL/min일 때 17.1 g/L ·hr 및 0.54 g/g이었으며, 최적 숙신산 생산성 및 이 때의 수율은 푸마르산염 농도 50 g/L 및 배지 공급 유속 1.0 mL/min일때 9.0 g/L · 및 0.90 g/g으로서 회분식 생물전환의 경우보다 더 우수하였다.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.183-189
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• 2014

내화성 및 내화학성이 우수한 현무암사의 표면에 회분식 방법에 의한 테프론 코팅 연구의 결과를 토대로 연속식 코팅 공정 인자를 도출하기 위한 연구를 수행하였다. 현무암사를 7,5 wt% 트리에톡시트리플루오로실란(TMTFPS)으로 연속적으로 전처리 한 후, 침투제로 0.25 wt% bis(2-ethylhexyl)sulfo succinate (DOS-Na)가 함유된 20 wt% 테프론 수분산액으로 딥 코팅한 후 2 m의 $120^{\circ}C$ 건조 챔버에서 12 m/mim의 속도로 건조한 후 2 m의 $380^{\circ}C$ 소성 챔버에서 40초간 소성하여 최종 $3.4g_f/D$의 인장 강도와 $2.3g_f/D$의 루프강도를 가지는 테프론이 코팅된 고내열 재봉사용 현무암사를 제조하였다.

• Journal of Microbiology and Biotechnology
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• 제7권2호
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• pp.127-131
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• 1997

Alkaline phosphatase (APase) was found to be inducible in Anabaena sp. strain CA Growth was less than control in presence of most amino acids except glycine and serine, but most amino acids enhanced APase activity. Highest APase activity was recorded in tyrosine supplemented culture followed by hydroxyproline, cystein, valine and glutamic acid. Threonine supplemented material showed lowest APase level (1.8 nmol/mg protein/min). Lactose, glucose, sodium pyruvate and succinate stimulated growth but not APase activity. APase activity was high in the presence of sucrose, mellibiose, mannitol, arabinose, maltose and sorbose, even though the growth in these supplements was less than in control. Organic phosphate sources supported good growth of the organism. Best growth occurred in presence of inorganic phosphate, adenosine diphosphate, fructose 1,6-diphosphate or ribulose 1,5-diphosphate, followed by other phosphorus sources tested. APase activity in presence of any of the organic phosphate sources was 3 to 5 fold low as compared to phosphate limited culture. Also, there was no APase activity in cultures grown on inorganic phosphate. These data indicate that most amino acids and a few carbohydrates (sucrose, mellibiose, arabinose and sorbose) are suitable for APase production. Lactose, glucose, pyruvate or succinate may be used as a carbon source during photoheterotrophic growth of the cyanobacterium. Glycine and serine are preferred nitrogen sources for its growth. Phosphate repressible APase activity has been found in Anabaena sp. strain CA.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2009년도 International Meeting of the Microbiological Society of Korea
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• pp.78-78
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• 2009

$^1H$ NMR spectroscopy coupled with multivariate statistical analysis was used for the first time to investigate metabolic changes in musts during alcoholic fermentation and wines during ageing. Three Saccharomyces cerevisiae yeast strains (RC-212, KIV-1116 and KUBY-501) were also evaluated for their impacts on the metabolic changes in must and wine. Pattern recognition (PR) methods, including PCA, PLS-DA and OPLS-DA scores plots, showed clear differences for metabolites among musts or wines for each fermentation stage up to 6 months. Metabolites responsible for the differentiation were identified to valine, 2,3-butanediol (2,3-BD), pyruvate, succinate, proline, citrate, glycerol, malate, tartarate, glucose, N-methylnicotinic acid (NMNA), and polyphenol compounds. PCA scores plots showed continuous movements away from days 1 to 8 in all musts for all yeast strains, indicating continuous and active fermentation. During alcoholic fermentation, highest levels of 2,3-BD, succinate and glycerol were found in musts with the KIV-1116 strain, which showed the fastest fermentation or highest fermentative activity of the 3 strains, whereas the KUBY-501 strain showed the slowest fermentative activity. This study highlights the applicability of NMR-based metabolomics for monitoring wine fermentation and evaluating the fermentative characteristics of yeast strains.

• 한국미생물·생명공학회지
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• 제17권3호
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• pp.213-218
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• 1989

Cloning을 위한 host와 vector의 이용 가능성을 타진하기 위해 호알칼리성 Bacillus속 K-17을 host로, pUB110과 pBD64를 vector로 사용하여 Bacillus속 K-17의 protoplast 형질전환조건을 검토하였다. 원형질체의 형성은 200$\mu\textrm{g}$/$m\ell$의 Iysozyme 을 처리하였으며, 원형질체 형성의 최적 온도, PH및 배양시간은 각각 4$0^{\circ}C$, 7.0 및 4시간으로 나타났다. 원형질체는 DM3 재생배지에서 재생시켰으며 0.8% agar, 0.5M sodium succinate 농도에서 가장재생이 좋았다. 형질전환시 PEG의 농도는 40%(w/v) PEG 6,000 30%(v/v)가 최적으로 나타났다. 형질전환체의 특성을 조사한 결과, plasmid 안정성은 pUB110이 pBD64보다 더 안정하였으며, 최대 효소활성은 비슷하였지만 효소 분비시간은 pUB110 은 2.5일, pBD64의 경우는 3일로 Bacillus속 K-17의 2일에 비해 약간 지연되었다.

• Applied Biological Chemistry
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• 제40권6호
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• pp.561-566
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• 1997

광합성세균을 이용하여 생물제초제의 하나인 ${\delta}-aminolevulinic$ acid(ALA)를 생산할 목적으로 자연계로부터 ALA 생산능력이 우수한 균주를 분리하고 ALA의 최적생산에 미치는 일부 배양특성을 검토하였다. 선정균주 KK-10을 동정한 결과 홍색비유황세균에 속하는 Rhodobacter capsulatus로 판명되었다. 본 균주의 ALA 생산성을 높이기 위하여 ALA 탈수효소의 저해제인 levulinic acid(LA)를 15 mM 농도로 배양중기에서 배양액에 첨가함으로써 ALA의 생산량은 약 20배(28 mg/l) 증가되었다. ALA의 전구물질인 glycine과 succinate를 각각 30 mM 복합첨가할 때 약 50배(73 mg/l)생산량을 나타내었고 전구물질의 첨가에 의해 ALA 합성효소의 생합성량은 2배 증가하였다. 분리균주는 전구물질 함유 배지에 15 mM LA를 대수기 중기부터 4회 연속첨가함으로써 85 mg/l 균체외 ALA를 생산하였다.